New GU Gobi Questions

Are ya having a problem with your rig? We'll try to help. Share your tech tips and experiences here. Dr. Billy Glaser, author of the "Unofficial 750 Ural Service Manual" site myural.com, is moderating this section.
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rebelpacket
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New GU Gobi Questions

Post by rebelpacket » Wed Oct 05, 2011 5:01 pm

Hey Folks!

Got my 2011 Gear-Up Gobi this past Saturday. I haven't driven my truck once since then... can't stop riding it! I'm at about 250 klicks on the odo now, and I understand that these bikes are not really "broken in" until somewhere around 5,000k.

That said, I've noticed some issues with the bike (which I have tried to correct), and I could use some guidance on.

#1. Jetting.

I'm at about 5,500 feet here in Bozeman, MT. For the first 180 km's or so, I left it stock, as I got it. The rig started right up when cold (no enricheners) and felt great. A couple klicks down the road once things had warmed up nicely, things changed. Off the line, it would bog so bad that I had to rev it up to 2-3K RPM's and slip the clutch (in first gear) just to get it moving. Once it was hot, it would stall repeatedly idling at stop-lights, and almost always required some throttle to keep it turning.

I found the pilot air screw was at about 1 1/4 turns out on both sides. The electrodes on the plugs we're a dark tan color, but everywhere else on the plug was black. Since then I've set the air screw at about 3/4 turn out and the bike seems to idle and perform marginally better (I don't have to slip the clutch when its hot to get moving in first). However, there is a noticeable "bog" spot from about 1/8-1/4 throttle (while moving).

My question is: Should I risk messing with the jetting at all before I'm at 1-2,000 km? Will the bike change dramatically enough after those miles to smooth out the transitions from idle to main jet? Or is this "just the way these bikes are" ?

I've go no complaints about the rig; just wondering if smooth jetting and throttle control is achievable (and worth it).
Riding in Colorado...
2011 Gear-Up Gobi
2000 BMW 1150GS
1971 BMW R75/5
1968 Honda S90

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Re: New GU Gobi Questions

Post by Latguy » Wed Oct 05, 2011 5:51 pm

Seems to me, yer new rig aughta run like a new rig! The carbs may not have been accurately set up - at 500km ya wanta change fluids and adjust valves and check timing and all that so after having handled that stuff and knowing that it's all good - TwinMax (or equivalent..) and careful carb adjustment and - voila!!! great running rig! OK, maybe it needs rejetting, too - but give it a little time...
At 5Kkm+ it'll shift better and be more "sprightly" and at 10Kkm+ even more so!
Of course, if ya wanta re-jet it, do it! The critters are set up mighty lean to satisfy the emissions regs and keep the catalytics happy - if the cats got away, ya could richen the mixture and it would probably run better...
Ride it like ya stole it in a third world country!
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Re: New GU Gobi Questions

Post by deeve » Wed Oct 05, 2011 6:30 pm

+1. I just synched my carbs after the 500km service and I was impressed at what a big difference it made in smoothness and better running.

DAVE
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Re: New GU Gobi Questions

Post by mgtibb » Wed Oct 05, 2011 8:03 pm

You may need a leaner slow jet if it's bogging down once the engine gets heated up. You may want to wait though, as winter is coming and your engine will run cooler and it probably won't bog down so much on take off. My bike does this also when it gets hot. If it's a really warm day I just turn the pilot screw to about 1/2 to 3/4 turns out and it cures it enough to not be annoying. Otherwise I'm about 1 and 1/2 turns out. The way you've described your plugs, it sounds a little rich to me. Do you know what size jets are in the bike and if the jet needle has been shimmed? Just for reference, if your bike starts up easy with no chokes and idles without any throttle input when the engine's cold, it's too rich at idle.
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Re: New GU Gobi Questions

Post by Lokiboy » Wed Oct 05, 2011 8:38 pm

mgtibb wrote:You may need a leaner slow jet if it's bogging down once the engine gets heated up. You may want to wait though, as winter is coming and your engine will run cooler and it probably won't bog down so much on take off. My bike does this also when it gets hot. If it's a really warm day I just turn the pilot screw to about 1/2 to 3/4 turns out and it cures it enough to not be annoying. Otherwise I'm about 1 and 1/2 turns out. The way you've described your plugs, it sounds a little rich to me. Do you know what size jets are in the bike and if the jet needle has been shimmed? Just for reference, if your bike starts up easy with no chokes and idles without any throttle input when the engine's cold, it's too rich at idle.
Question, so I don't screw it up (pardon the pun). When you describe turning out 1 to 1 ½ turns, what is your starting point? Would I turn CCW or CW from my existing settings to get to the starting point? :oops:
2011 Gear Up - "Erika"
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Re: New GU Gobi Questions

Post by Niteblues » Wed Oct 05, 2011 10:49 pm

The starting point is a 'soft seat'. That is, screw it all the way in, but softly so as not to damage the tip of the needle in there.
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Re: New GU Gobi Questions

Post by mgtibb » Wed Oct 05, 2011 11:20 pm

niteblues59 wrote:The starting point is a 'soft seat'. That is, screw it all the way in, but softly so as not to damage the tip of the needle in there.
Some tips to go along with what niteblues59 said. "soft seat" = screw the pilot screw in CW (looking up at it) gently until you just feel some resistance. Too far and you may damage the needle. From that point, count your turns CCW. Make sure they are full turns (360 degrees). I've seen people count 180 degrees as a full turn when they are not paying attention. If your less that 3/4 turn out or more than 2 turns (from the "soft seat") you may want to try a different size slow jet. And CW will make your idle mixture leaner, CCW = richer. Hope this helps.
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Re: New GU Gobi Questions

Post by markhas » Thu Oct 06, 2011 1:09 am

One way to keep track of where you are on your turns of the screwdriver is to note where the handle is oriented too. Often the handle will have the name brand or modle/part/stock number printed on it, making note of some detail will help to keep you on the straight and narrow.
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Re: New GU Gobi Questions

Post by S 854 » Thu Oct 06, 2011 7:46 am

markhas wrote:One way to keep track of where you are on your turns of the screwdriver is to note where the handle is oriented too. Often the handle will have the name brand or modle/part/stock number printed on it, making note of some detail will help to keep you on the straight and narrow.
+1 ...and measure your progress in 'half-turns'...
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Re: New GU Gobi Questions

Post by rebelpacket » Thu Oct 06, 2011 8:57 am

Thanks for the information chaps. After todays riding, I'm at 320kms, so I'll hopefully be cracking things open for the 500 service this weekend. I'll report back with my needles and jets then. I'll try setting my idle screw to 1/4-1/2 turns out and see if it improves.

I use the red screwdriver supplied with the Ural toolkit to adjust the pilot idle screw. Its got a nice protrusion that makes it pretty easy to tell where you are in the rotation. Clever fellows, those Russians.
Riding in Colorado...
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2000 BMW 1150GS
1971 BMW R75/5
1968 Honda S90

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Re: New GU Gobi Questions

Post by Msblu79 » Thu Oct 06, 2011 2:00 pm

1/4 to 1/2 turn may not be enough to start, bottom them lightly and turn CCW about 1 & 1/2 turns out. Try that to start with & adjust in/out as needed from there. :wink:
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Re: New GU Gobi Questions

Post by rebelpacket » Thu Oct 06, 2011 2:33 pm

Msblu79 wrote:1/4 to 1/2 turn may not be enough to start, bottom them lightly and turn CCW about 1 & 1/2 turns out. Try that to start with & adjust in/out as needed from there. :wink:
I already tried 1 & 1/2, then went to 1, and finally 3/4 (where I'm at now). Still bogs pretty bad.
Riding in Colorado...
2011 Gear-Up Gobi
2000 BMW 1150GS
1971 BMW R75/5
1968 Honda S90

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Re: New GU Gobi Questions

Post by Lokiboy » Thu Oct 06, 2011 4:17 pm

mgtibb wrote:
niteblues59 wrote:The starting point is a 'soft seat'. That is, screw it all the way in, but softly so as not to damage the tip of the needle in there.
Some tips to go along with what niteblues59 said. "soft seat" = screw the pilot screw in CW (looking up at it) gently until you just feel some resistance. Too far and you may damage the needle. From that point, count your turns CCW. Make sure they are full turns (360 degrees). I've seen people count 180 degrees as a full turn when they are not paying attention. If your less that 3/4 turn out or more than 2 turns (from the "soft seat") you may want to try a different size slow jet. And CW will make your idle mixture leaner, CCW = richer. Hope this helps.
Just the information I needed. Thanks
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
MKIII air filter
100,000 km and counting

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Re: New GU Gobi Questions

Post by rebelpacket » Mon Oct 10, 2011 7:39 am

As a follow-up; someone stole the cats out of my exhaust over the weekend.

When I discovered this, I figured it'd be best to sync the carbs in case there was any disruption in flow. After the sync, the off idle throttle response was better, but still bogged a good bit after running 50mph for an extended period.

I'm going to pull the carbs on Weds and see what my jetting is and see about getting smaller pilot/idle jets. The main seems to be performing just fine with whatever is in there, though I do think it'll open up with a K&N filter over stock.

I'll report back with a permanent solution when I have one!
Riding in Colorado...
2011 Gear-Up Gobi
2000 BMW 1150GS
1971 BMW R75/5
1968 Honda S90

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Re: New GU Gobi Questions

Post by markhas » Mon Oct 10, 2011 9:20 pm

rebelpacket wrote:As a follow-up; someone stole the cats out of my exhaust over the weekend.

When I discovered this, I figured it'd be best to sync the carbs in case there was any disruption in flow. After the sync, the off idle throttle response was better, but still bogged a good bit after running 50mph for an extended period.

I'm going to pull the carbs on Weds and see what my jetting is and see about getting smaller pilot/idle jets. The main seems to be performing just fine with whatever is in there, though I do think it'll open up with a K&N filter over stock.

I'll report back with a permanent solution when I have one!
As long as you have the carbs off read up on drilling the slides, lots of info here to guide you to the deed. Slides are made of plastic and you can drill the stuff with just your fingers twirlling the drill and a little down pressure. This will stop the stumbling and bogging down and quicken the recovery to idle or lower rpm when shifting. Drilling the slides is one of the best things you can do, you might find that you don't really need to change the jets... YMMV
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